pub fn longest_common_prefix(first: &str, second: &str) -> String {
if first.len() == 0 || second.len() == 0 {
return String::from("");
}
let first_bytes = first.as_bytes();
let second_bytes = second.as_bytes();
let mut index: usize = 0;
while first_bytes[index] == second_bytes[index] {
index = index + 1;
if index >= first_bytes.len() || index >= second_bytes.len() {
return String::from_utf8(first_bytes[0..index].to_vec()).unwrap();
}
}
return String::from_utf8(first_bytes[0..index].to_vec()).unwrap();
}